752 



ZOOLOGY 



SECT. 



liv 



CLp 



cavity by the conspicuous excretory apertures already described. 

 On either side is an aperture (ap. 1) placing the cavity of the sac in 

 communication with the pericardium, and the right and left sacs 

 communicate with one another orally and aborally. From their 

 posterior junction is given off a median diverticulum (Fig. 680, 

 med. s), into which the pancreatic follicles (pane.) project. 

 Through each excretory sac runs the corresponding afferent branchial 



vein, formed by the 

 bifurcation of the vena 

 cava, and surrounding 

 it are masses of gland- 

 ular tissue (Fig. 679, 

 ven. app), by whose 

 agency the process of 

 renal excretion (the 

 products of which, in 

 the shape of a nitro- 

 genous excretory sub- 

 stance called guanin, 

 are to be detected in 

 fenl the internal cavity) is 

 br.hl carried on. 



Reproductive 

 system. In the male 

 the testis (Fig. 681, te.) 

 forms a compact mass 

 of minute tubules 

 situated in the aboral 

 region of the body 

 and enclosed in a 

 capsule. The single 

 spermiduct (v. def.) is 

 a greatly convoluted 



F.o.eso.-Septa officinal, diagram of a median tube which leads from 



vertical section of a female specimen, to show the trie Cavity OI the Cap- 

 relations of the cavities, ap. aperture between the i , i ,- i rl 



secondary body-cavity (pericardium) and the lateral SU16 towards tne leit , 

 nephridial sac: br. ht. branchial heart ; cod. coelome; 



Ictl.s 

 coeL 



ink.s 



it opens into 



nephridial sac ; liv. liver ; med. s. median nephridial sac ; gated vesicula 



ov. ovary ; ov. ap. aperture leading from oviduct to & 7 . . N 



secondary body-cavity ; pane, pancreatic appendages ; dllS (VeS.), tO WillCil IS 



sh. shell ; st. stomach: ur. ureter; vent, ventricle. l^^rl <, rAn-nArAnv 



(From vogt and Jung, after Grobben.) appended a glandular 



body, the prostate 



(pr.). In the interior of the vesicula seminalis the sperms are 

 rolled up by the action of a system of grooves and ridges into 

 long narrow bundles of about 2 cm. in length, each of which 

 becomes enclosed by a chitinoid capsule of a narrow cylindrical 

 shape, forming a spermatophore (Fig. 682, B) ; at one end of 

 the spermatophore is a complicated apparatus of the nature 



